A wide variety of different types of storage systems are known. For example, some storage systems are configured to include multiple storage tiers, with different ones of the tiers providing different levels of performance or other characteristics. In such storage systems, data may be moved from one tier to another within a given storage system based on access frequency of the data or other factors. These and other types of tiered or non-tiered storage systems may be shared by multiple host devices of a compute cluster. However, problems can arise in such arrangements when a storage array or other type of storage system attempts to provide different service level objectives (SLOs) for processing of different types of input-output (IO) operations from the host devices that share that storage system. For example, in some implementations there may be hundreds of different host devices which share the same storage system, making it very difficult for the storage system to achieve the desired SLOs for the IO operations of all of its associated host devices. This is due at least in part to the utilization of artificial delays in storage system queues. Such delays are intended to increase certain response times in order to meet the particular requirements specified by lower-performance SLOs. These actions can increase queue congestion within the storage system, resulting in one or more of the host devices receiving excessive “queue full” messages from the storage system.